Some of the most challenging and time consuming issues to diagnose on a vehicle continue to be noise, vibration and harshness problems, but some new technology brings a new dimension in noise vibration harshness diagnostics.
The symptoms around the subject of noise, vibration and harshness are subjective as each driver has a different level of what may be an acceptable amount sensed whilst driving, proving difficult to pinpoint, even for the most experienced technician.
Traditional methods require a technician to determine the frequency (hertz) of the vibration during a road test. From this they would need to figure out which component was rotating at the required RPM to cause the vibration frequency. This requires directly measuring the dimensions of various components or finding the dimensions in technical specifications, and applying mathematical calculations to arrive at a conclusion.
The Pico Diagnostics NVH software provides the capability to tie the vibration detected to a source in a much easier, more objective way. e.g. driveline, propshaft, tyre and wheel, engine and engine accessories.
Now in 2019 and into the future, the PicoScope NVH diagnostic kit provides an accurate analysis of vehicle noise, vibration and harshness conditions, offering a new dimension for OEM’s to consider.
Using your own laptop or tablet display to view, this system combines a fast capture and analysis of vehicle data with a clear, easy to read presentation of test drive results and actions on all vehicle types including the latest diesel, gasoline, hybrid and electric vehicle technology.
Once this data has been collected via the test drive, it can then be analysed in great detail and compared to previous captures (prior to adjustment) or against other vehicles. Often what is perceived by the customer to be a “problem vibration” can, in fact, be a characteristic of the vehicle or model.
Now you can present and compare objective data with test results from other similar vehicles to reassure the end-user that everything is normal. Alternatively, comparing data may highlight a problem with the vehicle and the measurements taken can give the technician the information needed to confidently proceed with a repair.
Below are just a few of the typical scenarios experienced where a Pico NVH kit can be used:
- Cabin vibrations at speed, e.g caused by misaligned prop shaft, poor engine or exhaust mounts
- Engine vibrations throughout the entire RPM range
- Clutch shudder or vibration
- Transmission and bearing whine
- Auxiliary drive noise
- Brake shudder
- Steering vibrations
- Fast balancing of driveline
The root of all NVH problems is a vibration. In some cases, these are unwanted or unexpected vibrations, and in other cases, they are normal and always present (e.g. engine combustion), but they are noticeably felt when transmitted through to the passenger compartment.
Sound is simply a vibration that is transmitted through the air and is heard when it reaches a person’s ear. Although the perfect hearing range is 20 Hz to 20 kHz, most of us are more like 100 Hz to 15 kHz at best. Vibrations are usually felt at frequencies below 200 Hz, and in the overlapping frequency range vibrations can be both felt and heard.
In order to deal with this frequency range effectively, the PicoDiagnostics NVH kit contains both high resolution microphones (for sound), and highly sensitive accelerometers (for even low levels of vibrations).
The PicoDiagnostics NVH kit from Pico Technology can be the answer to the many NVH problems facing technicians. The NVH interface supplies power to the amplifier while transmitting vibration and sound signals to the oscilloscope.
The detailed software provides a real-time diagnosis for the technician, in the form of either: a bar graph, line graph, frequency chart, 3D frequency chart, RPM order, road speed view or a time domain view.
The ability to start the recording before a road test and playback and analyse the recording back in the workshop, ensures that the driver’s attention safely remains on the road. Saving the recordings couldn’t be easier. Much like Pico’s other automotive software, you can simply save the file to your laptop’s hard drive, and easily share the results with your colleagues etc to prove an improvement. The software includes on screen, step by step instructions to follow and comprehensive help to diagnose accurately, and then suggests corrective action to proceed with.
The PicoDiagnostics NVH kit makes use of the PicoScope Automotive oscilloscopes and are available in a number of configurations to suit your needs. You can be sure that your investment in the PicoDiagnostics NVH kit will benefit your business without the need for further spending. If you already have a Pico Automotive oscilloscope, you are halfway there.
After repairs are made the technician can prove the fix with the PicoScope NVH software and present the results of the repair to the customer in a most professional manner.
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